Device for mixing gas and air



May 13, 1947. E. RATHBUN DEVICE FOR MIXING GAS AND AIR Filed Aug. 8,1945 INVENTOR E'dwardEaZhbuw a flmwlw Patented May 13, 1947 UNITEDSTATES PATENT OFFICE DEVICE FOR MIXING GAS AND AIR.

Edward Rathbun, Toledo, Ohio, assignor to The Rathbun-Jones EngineeringCompany, 'lloledo, Ohio, a corporation of Ohio Application August 8,1945, Serial No. 609,509

6 Claims. 1

This invention relates to Diesel. engines particularly of the typeutilizing a gas and oil mixture for fuel.

Diesel engines of the type employing gas or oilor a gas and oil mixturemay at one time use natural gas and at another time use producer gas ora mixture of these kinds of gas. The B. t. u. content of producer andnatural gas, of course, varies considerably and it is desirable thatconvenient adjustment be made possible to adapt the engine for the B..t. u. content of the particular gas employed at the time. It is adesideratum, therefore, to provide an oil-gas engine with. a simple andconvenient device by which the engine may be conveniently adapted forgases of different B. t. u. content, such, for example, as producer andnatural gas.

It is an object of this invention to produce a simple and inexpensiveappliance fo a gas-oil engine by which the engine can be adjusted forgases of' different B. t. u. content, thereby materially to enhance theefliciency of the engine operation.

An embodiment of the invention is shown by way of illustration but notof limitation on the accompanying drawings in which Figure 1- is atransverse section on a some- What reduced scale taken on the line l--lof Figure 2, illustrating a throttle box assembly for a gas-oil engine;

Figure 2. is a longitudinal section on a somewhat enlarged scale takenon the line 2-2 of Figure 1;, showing particularly the adjustable sleevewhich is-shifted according to the B. t. u. content ofthe. gas used andarranged in the position assumed when the engine is using gas of arelatively low B. t. u. content such as producer gas; and

Figure 3 is a fragmentary sectional view similar to Figure Zshowing theadjustable sleeve in the-position assumed when the gas employed is of arelatively high B, t. u. content such, for example, as natural gas.

The illustrated embodiment of the invention comprises an elongatehousing In having an end wall; It with which a fuel supply tube [2 isintegral, a. portion of the tube projecting well insideot the housingand having a flanged mouth l k and a constricted throat l4 providing aventuri. The portion of the tube l2 which projects outside of thehousing is formed with a flange l5 for connection, either directly orindirectly, to the intake manifold of a Diesel engine (not shown).

Extending from the housing ill and substantially in alignment with thetube mouth I3 is a tubular extension l6 which is formed with an outwardflange l1 and clamped between a fitting or cap [8 and the flange I! bybolt and nut assemblies 2!] are a spacer ring 2| and a flange 22integralwith a cylindrical sleece 23 which closely fits the insidesurface of the housing extension it. The fitting or cap [8 is suitablyapertured to. admit air which is drawn into the venturi or fuel supplytube l2.

The sleeve 23 is formed with a pair of diametrically opposedlongitudinally elongate slots 24 to receive a pintle 25 which hasbearing in the walls of the housing extension l6 and carries a butterflyvalve 26. Suitable lever mechanism 2] is provided for rocking the pintleto effect thedesired adjustment of the valve 26.

In the position of the parts shown on Figure 2, it will be observed thatthe spacer ring 2| is interposed between the flanges ll and 22, therebypositioning the sleeve 23 outwardlywith respect to the fuel supply tubeI2 and so that the inner end of the tube is substantially flush with theinner end of the extension It. For a purpose which will hereinafter beexplained, the sleeve 23 is formed with an annular row of apertures 28which are adjacent to but spaced from the inner end of the sleeve.

A portion of the housing IE! at one side of the fuel intake tube [2 isflattened as indicated at 29 and suitably secured thereto is a valvehousing 30 which is formed with outlet passages 3| regis- .tering withports 32 in the side wall 29 of the housing. A double spool valve 33 ofany suitable or well-known construction controls the communicationbetween the Valve passages 3| and the interior 34 of the valve housing30; Gas, such as natural or producer gas, may be introduced to theinterior 34 of the housing through an inlet port or opening 35 and fromthence, upon opening or unseating of the valve 33, a gas flows throughthe passages 3| and ports 32 to the inside of the housing in the regionof the space indicated at 36 between the mouth l3 of the intake tube I2and the housing wall II and thence passes in the direction of the arrowsindicated on Figure 2, to the inside of the tube 12 and at the same timedraws or aspirates air admitted through the fitting or cap it.

In order for the engine to operate at maximum efiiciency, it isimportant not. only that the gas and air be properly mixed, but that,depending upon the quality of the gas, the flow of the latter becontrolled before it reaches the Venturi or diffuser tube l2. It isdesirable that relatively free flow of gas be afforded from the space 36to the diffuser tube [2 in the case of producer or sewer gas and forthat reason, the ported sleeve 23 is disposed in the position shown inFigure 2 and when producer or sewer gas is used, it may be desirable,under some conditions, to actuate the butterfly valve 26 to close oif tosome extent the air supply, thereby to increase the suction drawing inthe gas to the fuel tube 12.

When natural gas or gas having a higher B. t. u. content is used, thespacer ring 2| is removed and applied in the position indicated inFigure 3, thereby advancing the sleeve 23 to a position in which theinner end abuts against and closes the mouth I3 of the Venturi tube, Inthat event, the gas from the space 36 then passes in the direction ofthe arrows as shown in Figure 3, and through the annular row ofapertures 28. This not only to some extent restricts the flow of gas butalso directs it in such manner that it is more fully and satisfactorilymixed with the air drawn through the cover plate or cap l8. Manifestly,the gas drawn in in this manner will mix more thoroughly with the airstream thereby materially enhancing combustion. The size of theapertures 28 may be varied according to the B. t. u. content of the gas.

From the above description, it will be manifest that I have provided anextremely simple fool proof and reliable device for regulating theairgas mixture supplied to the engine manifold in accordance with the B.t, u. content of the gas. By an extremely simple adjustment, the sleeveis positioned either for use in connection with sewer or producer gas orin the position of use in connection with natural gas. As aboveindicated, the size of the holes in the sleeve may be varied as desired,depending upon the B. t. u. content of the gas which, of course, ispredetermined for the particular situation where the Diesel engine is tobe operated.

It is to be understood that numerous changes in details of construction,arrangement and oper ation may be effected without departing from thespirit of the invention especially as defined in the appended claims.

What I claim is:

1. In a Diesel engine, means for introducing a gas and air mixture tothe intake manifold of the engine, said means including a Venturi tube,and adjustable means for regulating the volume of gas delivered to saidtube, said last means including a ported sleeve adapted for adjustmentto either of two positions one of which affords relatively free flow ofgas to the tube the other effecting abutment between the sleeve and thetube thereby to cause the gas to flow through ports in said sleeve.

2. In a Diesel engine, a device for mixing gas and air for delivery tothe intake manifold, said device comprising a housing, a fuel supplyVenturi tube having its mouth disposed within the housing, means fordelivering air to the tube substantially coaxially of the tube mouth,means for delivering gas to the housing so that the same passes aroundthe tube and into same around the tube mouth, and ported meansadjustable in said housing and adapted to engage the tube mouth forenhancing the air-gas mixture drawn into the Venturi tube in accordancewith the B. t. u. content of the gas, said ported means comprising asleeve slidable in the air inlet passage and movable from a positionallowing free flow of gas to the Venturi tube to a position in contactwith the Venturi tube whereby the gas passes to the Venturi tube throughthe ports in the sleeve.

3. In a Diesel engine, an air and gas mixing device as claimed in claim2 in which the sleeve is formed with an outwardly extending flange and aspacer ring adapted to be selectively arranged on one side or the otherof said flange to position the sleeve in one position of adjustment orthe other.

4. In a Diesel engine, an air and gas mixing device as claimed in claim2, in which the sleeve is formed with longitudinally elongate slots, abutterfly valve disposed within the air passage for controlling theamount of air and influencing the amount of gas drawn into the Venturitube, a pintle for the valve having portions disposed in said slots forholding same against turning movements and guiding the sliding actionthereof.

5. In a Diesel engine, a device for mixing gas and air for delivery tothe intake manifold, said device comprising a housing, a fuel supplyVenturi tube having its mouth disposed within said housing. means fordelivering air to the tube substantially coaxially with said Venturitube, means for delivering gas so that the same passes into said tubefrom about its periphery, a ported sleeve adapted for sliding movementbetween two positions of adjustment, one of which affords relativelyfree flow of gas to the tube, the other of which eiiects abutmentbetween said sleeve and the flared edge of said Venturi tube to causethe gas to flow through ports, and an air control valve in said sleeveaiding the control of the air and gas ratio.

6. In 21 Diesel engine, a device for mixing gas and air for delivery tothe intake manifold, said device comprising a housing, a fuel supplyVenturi tube having an outwardly flared mouth of greater diameter thanthe throat disposed within said housing, said housing also defining anair passage for the delivery of air substantially coaxially with saidVenturi, means for delivery of gas so that the same passes into saidtube from about the periphery of said flared mouth, a ported sleeveslidable to two positions of adjustment in said housing passage andadapted in one position to afford the relatively free flow of air to thetube and in the other position to abut said Venturi mouth thereby tocause the air to flow through ports, said outwardly flared mouthenhancing the mixture of the gas and air before entrance into saidthroat portion, and means for positively securing said adjustable sleevein either of said positions.

EDWARD RATHBUN.

REFERENCES CITED ihe following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,366,322 Foster Jan. 2, 19452,321,483 Haedike June 8, 1943 2,233,523 Forgar Mar. 8, 1941 1,874,238Gallahan Aug. 30, 1932 1,585,142 Gillett May 18, 1926

